1. Field of the Invention
This invention relates to connectors for optic fibre cables.
2. Acknowledgement of Prior Art
Optic fibre cable is becoming more and more important in the transmission of data over distance but optic fibre cables present special problems in connecting one cable to another or to an appliance for receiving or transmitting light. Particular problems that arise are the proper alignment of the fibres and the attainment of a tight fit in the connection. When any plug is connected into a socket it is rarely a completely tight fit at its leading face with the adjacent surface of the socket. For most plugs this is not important since connection is through the circumference of the respective plug and socket. For fibre optic cables however, connection is through the flush faces of the optic fibres. If one face does not make perfect connection with the adjacent face of a complementary member light is lost and quality of transmission is affected. It is therefore extremely important that, for fibre optic cables an optimized tight fit of the face at the end of the cable is desirable. Various attempts have been made to provide such an optimized fit and some of these are set out in:
______________________________________ U.S. Pat. No. 5,717,802 Briggs et al. Feb. 10, 1998 U.S. Pat. No. 5,444,806 deMarchi et al. Aug. 22, 1995 U.S. Pat. No. 5,097,525 Garcia et al. Mar. 22, 1992 U.S. Pat. No. 4,834,487 Abendschein et al. May 30, 1989 U.S. Pat. No. 4,793,683 Cannon, Jr. et al. Dec. 27, 1988 U.S. Pat. No. 4,193,663 Timmermann Mar. 18, 1980 U.S. Pat. No. 5,414,790 Lee et al. May 9, 1995 U.S. Pat. No. 5,594,825 Kawasaki et al. Jan. 14, 1997 U.S. Pat. No. 5,542,015 Hultermans July 30, 1996 U.S. Pat. No. 5,230,032 Muzslay July 20, 1993 U.S. Pat. No. 5,212,752 Stephenson et al. May 18, 1993 U.S. Pat. No. 5,170,452 Ott Dec. 8, 1992 U.S. Pat. No. 4,798,431 Clark et al. Jan. 17, 1989 U.S. Pat. No. 4,812,007 Lukas Mar. 14, 1989 ______________________________________
These patents are exemplary of the large number of fibre optic cable connectors which have been provided. Of these patents some of them, for example U.S. Pat. No. 4,834,487, show optic fibre cable plugs in which the plug itself is pressed forwardly by a spring so that the plug is biased into the socket. This is not a wholly satisfactory solution to the problem since the end of the fibre optic cable itself may become worn or may not project far enough from the plug to make a perfect fit with its mating member. It would be preferable to bias the fibre optic cable itself within the plug so that when the plug is seated firmly in the socket the fibre optic cable is biased to project from it towards its mating member. Such a situation is described in U.S. Pat. No. 5,717,802 to Briggs et al. U.S. Pat. No. 5,717,802 shows a spring biased fibre optic cable projecting from a plug body. A bearing for the spring is provided by shoulders of cantilevered members of the plug body. The cantilevered members, are snapped into position and are held in that position by means of a shoulder formed in the casing of the optic fibre cable.